Determination of Benzo[a]pyrene in Mainstream Cigarette Smoke by Online Comprehensive Two-dimensional Liquid-Gas Chromatography

An online comprehensive two-dimensional liquid-gas chromatography method was developed to determine the benzo[a]pyrene (B[a]P) in mainstream cigarette smoke. The B[a]P in mainstream cigarette smoke was collected by a cambridge filter pad, then the pad was extracted with cyclohexane and the extract was quantitatively analyzed by online LC-GC/MS with B[a]P-D12 as an internal standard. After direct injection into the performance liquid chromatography, the benzo[a]pyrene in the samples were separated by micro silica gel column and cut into the gas chromatography. After draining the solvent, the benzo[a]pyrene was separated by capillary column gas chromatography warming and detected by mass spectrometry detection. By using silica gel column chromatography and gas chromatography-mass spectrometry in combination, the benzo[a] pyrene in the mainstream cigarette smoke was directly detected without any sample pretreatment. The sample injection volume of the method could reach 40 mu L each time, which was far greater than that of conventional gas chromatography-mass spectrometry (2.0 mu L of sample injection volume), resulting in an increasing analysis sensitivity of 20 times. The linearity range of the method (R-2 = 0.999) was in the range of 0.08 ng/L to 50 ng/L. The recoveries at three spiked levels ranged from 94.2% to 105.5% and the limit of detection was 0.09 ng/cig. This method was applied for the determination of benzo[a]pyrene in 14 kind cigarettes in Chinese marked and the reference cigarettes 2R4F, and the determination results were consistent with GB/T21130-2007 method.